[Generator] Prevent copying resources to installation directory when `SKIP_INSTALL` is `YES`

CHANGELOG.md

@@ -12,6 +12,10 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
   [Boris Bügling](https://github.com/neonichu)
   [#3920](https://github.com/CocoaPods/CocoaPods/pull/3920)
 
+* Prevent copying resources to installation directory when `SKIP_INSTALL` is enabled.  
+  [Dominique d'Argent](https://github.com/nubbel)
+  [#3971](https://github.com/CocoaPods/CocoaPods/pull/3971)
+
 ##### Enhancements
 
 * Add `--sources` option to `push` command.

lib/cocoapods/generator/copy_resources_script.rb

@@ -160,7 +160,7 @@ EOS
 
 mkdir -p "${CONFIGURATION_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}"
 rsync -avr --copy-links --no-relative --exclude '*/.svn/*' --files-from="$RESOURCES_TO_COPY" / "${CONFIGURATION_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}"
-if [[ "${ACTION}" == "install" ]]; then
+if [[ "${ACTION}" == "install" ]] && [[ "${SKIP_INSTALL}" == "NO" ]]; then
   mkdir -p "${INSTALL_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}"
   rsync -avr --copy-links --no-relative --exclude '*/.svn/*' --files-from="$RESOURCES_TO_COPY" / "${INSTALL_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}"
 fi